Process for forming a non-woven,fiber web

ABSTRACT

A PROCESS FOR LAYING DOWN FIBERS IN A CYLINDRICAL OR MODIFIED CYLINDRICAL SHAPE FOR FORMING A NON-WOVEN FIBER WEB HAVING AN OPENED, LONGITUDINALLY EXTENDING CENTRAL PORTION. SAID APPARATUS HAS A ROTATING FIBER CONDUIT FOR HELICALLY PLACING LAYERS OF THE FIBERS BETWEEN TWO FORMING ELEMENTS AND MEANS FOR ENTANGLING THE POSITIONED FIBERS.

April 16, 1974 055 ETAL PROCESS FOR FORMING A NON-WOVEN, FIBER WEB 2. Sheets-Sheet 1 Original Filed March 9, 1970 OOOOO INVENTORS R. G. VOSS R; D. RAMSAY ATTORNEYS April 16, 1974 055 ETAL PROCESS FOR FORMING A NON-WOVEN, FIBER WEB 2 Sheets-Sheet Original Filed March 9, 1970 FIG. 3

FIG. 4

United States Patent 3,804,936 PROCESS FOR FORMING A NON-WOVEN, FIBER WEB Raymond G. Voss and Ray D. Ramsay, both Phillips Petroleum Company, Bartlesville, Okla. 74003 Original application Mar. 9, 1970, Ser. No. 17,397, now Patent No. 3,647,597, Mar. 7, 1972. Divided and this application Sept. 29, 1971, Ser. No. 184,790

Int. Cl. D04h 11/00 US. Cl. 264-93 9 Claims ABSTRACT OF THE DISCLOSURE A process for laying down fibers in a cylindrical or modified cylindrical shape for forming a non-woven fiber web having an opened, longitudinally extending central portion. Said apparatus has a rotating fiber conduit for helically placing layers of the fibers between two forming elements and means for entangling the positioned fibers.

This is a divisional application of copending application Ser. No. 17,397, An Apparatus for Forming a Nonwoven Web, filed Mar. 9, 1970 and issued Mar. 7, 1972, as US. 3,647,597.

This invention resides in a process for forming a cylindrical or modified cylindrical, non-woven, fiber web. In another aspect, this invention resides in a process for forming a substantially continuous, cylindrical or modified cylindrical, non-woven fiber formed of reinforcing elements and a multiplicity of fibers.

One method of forming a non-woven fiber web is by carding and cross lapping. In this method, individual fibers are aligned in a common direction and thereafter laid down in contacting, cross lapping layers to form a material of generally rectangular configuration. This method requires machinery having a large number of reciprocating, moving parts that are expensive and require large amounts or supervision and maintenance.

It is an object of this invention to provide a process for forming a non-woven fiber web. Another object of this invention is to provide a process for forming a fiber web of the above-described type that is of cylindrical or modified cylindrical configuration. Yet another object of this invention is to provide a process for forming a non-woven web of the above-described type with an apparatus that is less expensive and requires less supervision and maintenance than heretofore utilized non-woven, fiber web forming machinery. Other aspects, objects and advantages of the present invention will become apparent from a study of the disclosure, the appended claims, and the drawing.

The drawings are diagrammatic frontal views in partial cross section showing the apparatus used in the process of this invention. FIG. 1 is a view of the web forming apparatus and associated equipment used in this invention, FIG. 2 is an enlarged view of an outlet end portion of a fiber conduit of the apparatus, FIG. 3 is a crosssectional view of an embodiment of the resultant fiber web, and FIG. 4 is a cross-sectional view of another embodiment of the resultant fiber web.

Referring to FIG. 1, a forming element 2 is positioned within a chamber 4 of a housing 6. The forming element 2 is maintained in coaxial alignment with the housing 6 and has dimensions sufiicient to space the forming element a distance from the walls 8 of the housing 6 over the entire length of the forming element 2 thereby forming an annulus 10 between the two elements 2, 6. Although the elements 2, 6 can be of cylindrical configuration, it is preferred that the lower end portions -12, 14 of the forming element 2 and housing 6 each be of a cylindrical configuration tapering toward the outlet end 16 of the housing 6 in order to provide compressing forces to fibers passing through the annulus 10.

At least one fiber conduit 18, preferably a plurality of conduits, each having an outlet end 20 is positioned Within the annulus 10 at an upper end portion 22 of said annulus 10. The conduits 18 are connected at an inlet end 26 to a rotating head 24 for rotating the conduits 18 about the forming element 2 within the annulus 10 and passing fibers to and through the conduit 18 and into the annulus 10. The rotating head 24 is driven by a power means (not shown) at preferably a constant rate of speed relative to the discharge rate of the fibers from the conduit to lay down a layer of fibers that is substantially of uniform dimensions. A follower 28, better seen in FIG. 2, is preferably attached to a side of the outlet end 20 of each fiber conduit 18. The follower 28 extends downwardly and outwardly in an opposed direction relative to the direction of movement of the conduit 18 and into contacting relation with the layer of fibers within the annulus 10 for following the outlet end 20, compacting the fiber layer, and smoothing the upper surface of the layer.

The forming element 2 has a chamber 30 opening on av first end portion 32 thereof and a plurality of relatively small openings 34 extending through walls 36 of the forming element 2 communicating the annulus 10 with the chamber 30 of the forming element 2. The openings 34 of the forming element 2 are at a location lower in elevation than the outlet end 20 of the fiber conduits 18.

A conduit ring 38 is mounted around an outer surface of the housing 6 at a location lower in elevation than the outlet end 20 of the fiber conduit 18. A plurality of relatively small openings 40 are formed through an inner wall 42 of the ring 38 communicating a chamber 44 of the ring 38 with the outer surface of the housing 6. The ring 38 is sealably and rotatably mounted on the housing 6 and covering a plurality of relatively small openings through the walls 8 of the housing 6. A power means 48 is associated with the ring 38 for rotating the ring about the housing and intermittently passing the small openings 40 of the conduit ring 38- adjacent the small openings 46 of the housing 6. A blower 50, or pressurized gas source, is attached to the ring 38 in communication with the chamber 44 of the ring 38 for passing gas, preferably air, through portions of the relatively small openings 40 of the conduit ring 38, adjacent openings 46 of the housing 6, the adjacent fiber web positioned within the annulus 10, the small openings 34 of the forming element 2, and into the chamber 30 of said forming element 2. The air passing through portions of the fiber web causes the fibers of the web to further interlock one with the other. The air entering the chamber 30 of the forming element 2 from the web via openings 40 is discharged through the opening 54 on the first end portion 32 of said chamber 30. An air discharge conduit 56 is connected to the forming element 2 in communication with the chamber 30 for discharging air from the chamber 30. The discharge conduit extends through an upper end 58 of the housing 6. A guiding means 60 is preferably positioned between the discharge conduit 56 and the upper end '58 of the housing 6. The guiding means 60 has a plurality of openings extending therethrough for introducing a plurality of web reinforcing elements 62, such as cotton or polyester spun yarn for example, into the annulus 10 for contacting and incorporating said element 6-2 into the fiber web 52.

A fiber blower 64 is attached to a fiber reservoir 63 and in communication with the fiber conduit 18 through conduit 65 for passing fibers through the conduit and into the annulus 10 to form the fiber web 52. A conduit 3 66 is in communication with the annulus '10 at a location above the outlet end 20 of the fiber conduit 18 for removing air from the annulus 10. The discharge conduit 56 and conduit 66 are preferably attached to the intake end of the blower 64 through separating means 68, preferably a cyclone separator or the like, for removing any fibers present in the two streams of air discharging from elements 2, 6. A mixing means 70 can be associated with the fiber reservoir 63 and conduit 65 for adding bonding material to the fibers where such ma-' terial is desired to be incorporated with the fiber web 52.

A pair of rollers 72, 74 can be positioned adjacent the outlet end 16 of the housing '6 with the fiber web 52 emitting from the housing 6 being positioned between said rollers 72, 74. A drive means 76 can be attached to at least one of the rollers for urging the fiber web 52 from the annules 10 and a heating means 78 can be attached to at least one, preferably both, of the rollers 72, 74 to increase the temperature of the fiber Web 52. The heating means 78 is particularly advantageous where bonding material is incorporated with the fibers and where heat alone is utilized to seal the fibers one to the other. The rollers 72, 74 can also be urged one toward the other to compress the walls of the cylindrical fiber web together. Examples of bonding material that can be used are epoxy resins, or unsaturated polyester resin, and the like. Where heat alone is utilized to fuse portions of the 'web one to the other, the fibers are comprised of thermoplastic material and their temperature is increased by the heated rollers 72, 74 to a value generally in the range of about 350 to 50 -F.

Although the forming element 2 and housing 6 have here been described as forming an annulus 10 having a cylindrical configuration, it should be understood that these elements 2, -6 can be modified to have other configurations so long as the fiber web 52 is integrally formed having an open central portion 90, as shown in FIG. 3. For example, the web 52 can have a cross section defined by two elongated parallel extending web sides joined at each end one to the other by curved end web portions to resemble a race horse track-like configuration. Such a configuration lends itself particularly to a process wherein the walls of the fibers 52 are fused or connected one to the other by the rollers 72, 74, for example, to form a two-ply sheet of non-woven fiber web as shown in FIG. 4.

In the operation of the method, fibers such as polypropylene, polyethylene, cotton, polyester, rayon, nylon and blends of two or more of these in the fiber reservoir 63 are continuously blown by air from the fiber blower 64 into the upper end portion of the annulus 10 to form a continuous layer of fibers and form a fiber web 52. The outlet end of the fiber conduit 18 can be rotated to move along a circular pathway about the annulus to lay down within the annulus 10 a contiguous layer of fibers having a helical configuration. A plurality of air streams are passed from the blower 50 through the layers of fibers within the annulus 10 for interlocking the fibers together to form a web of fibers having an opened longitudinally extending central portion. The fiber web 52 is substantially continuously removed from the outlet end 16 of the housing 6. Rollers 72, 74 can be provided to facilitate removal of the fiber web 52 and increase the temperature of the fiber web 52.

The air flowing into the annulus 10 with the fibers is preferably returned to the fiber blower 64 via separating means 68 in order that fibers contained therein can be reinjected into the annulus 10. Air discharging from the 4 chamber 30 of the forming element 2 is also preferably discharged into the separating means 68 for removal of fibers entrained in the air stream.

By providing the process of this invention, a nonwoven cylindrical or modified cylindrical configuration having properties similar to carded and cross lapped nonwoven fiber webs can be formed without the use of reciprocating machinery elements.

Other modifications and alterations of this invention will become apparent to those skilled in the art from the foregoing discussion and accompanying drawing, and it should be understood that this invention is not to be unduly limited thereto.

What is claimed is:

1. A process for forming a non-woven web of fibers comprising:

laying down continuous layers of fibers along and within the first end portion of an annulus formed between two spaced-apart coaxial forming elements; moving the fiber layers longitudinally through the annulus; and passing a plurality of air streams through the layers of fibers within the annulus to interlock the fibers together and form a resultant unitary integral web of fibers having an opened longitudinally extending central portion.

2. A process, as set forth in claim 1, including introducing a plurality of web reinforcing elements into the annulus while laying down the layer of the fiber elements in contact with said reinforcing elements to provide reinforcing elements in the resultant web.

3. A process, as set forth in claim 1, including mixing a bonding material within the fibers being laid down within the annulus to form a bonded resultant web.

4. A process, as set forth in claim 1, including increasing the temperature of the web of the fibers to seal the fibers together.

5. A process, as set forth in claim 2, including mixing a bonding material within the fibers being laid down within the annulus to form a bonded resultant web.

6. A process, as set forth in claim 2, including increasing the temperature of the web of the fibers to seal the fibers together.

7. A process, as set forth in claim 1, including recovering the air streams after their passage through the fibers and separating fibers entrained in said recovered air streams.

8. A process, as set forth in claim 5, including recovering the air streams after their passage through the fibers and separating fibers entrained in said recovered air streams.

9. A process, as set forth in claim 6, including recovering the air streams after their passage through the fibers and separating fibers entrained in said recovered air streams.

References Cited UNITED STATES PATENTS 3,494,991 2/1970 Mazzio et al 264121 3,341,890 9/1967 'Oja 264-421 FOREIGN PATENTS 507,476 6/1939 England 264121 DONALD J. ARNOLD, Primary Examiner I R. HALL, Assistant Examiner US. Cl. X.R. 264-113, 121

I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3 H 3 Dated: April 16 197 Patent No Raymond G. Voss et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: I

Column 1, lines b,-5, after "Ramsay," delete "both c/o Phillips Petroleum Gemany, Bartlesville, Okla. 716303" and insert Bartlesville Oklahoma 7&003, aesignors to Phillips Petroleum Company, a corporation of Delaware Signed and sealed this 17th day of September 1974,

(SEAL) Attest:

C. MARSHALL DANN I Commissioner of Patents MeCOY M. GIBSON JR, I Attesting Officer 

